The present invention is directed to an improved
electroplating method,
chemistry, and apparatus for selectively depositing
tin / lead solder bumps and other structures at a high
deposition rate pursuant to manufacturing a microelectronic device from a workpiece, such as a
semiconductor wafer. An apparatus for plating solder on a microelectronic workpiece in accordance with one aspect of the present invention comprises a reactor chamber containing an
electroplating solution having free ions of
tin and lead for plating onto the workpiece. A chemical
delivery system is used to deliver the
electroplating solution to the reactor chamber at a high flow rate. A workpiece support is used that includes a contact
assembly for providing electroplating power to a surface at a side of the workpiece that is to be plated. The contact contacts the workpiece at a large plurality of discrete contact points that isolated from
exposure to the electroplating solution. An
anode, preferably a consumable
anode, is spaced from the workpiece support within the
reaction chamber and is in contact with the electroplating solution. In accordance with one embodiment the electroplating solution comprises a concentration of a
lead compound, a concentration of a
tin compound, water and
methane sulfonic acid.